Clamping jaw for clamping of a workpiece

ABSTRACT

A clamping jaw for the clamping of a workpiece, with a body and several clamping inserts arranged in mounting openings of the body made of a sintered material. The clamping inserts are designed in the form of cylindrical pins projecting relative to an end surface of the body and inclined relative to a lower base surface of the body with a clamping edge for forcing the clamping inserts into the workpiece.

FIELD OF THE DISCLOSURE

The disclosure relates to a clamping jaw with a body and severalclamping inserts arranged in mounting openings of the body made of asintered material.

BACKGROUND

Such a clamping jaw is known from EP 2 724 817 A1. Several triangularrecesses are made in the clamping surface of a body facing theworkpiece, into each of which a triangular clamping insert made ofsintered solid carbide material is inserted. However, both production ofthe body and production of the clamping inserts in such a clamping jaware relatively demanding and therefore associated with the correspondingcosts. Such triangular clamping inserts also require relatively largedesign space in depth so that the lateral accessibility can berestricted.

A device for fixing the positions of parts in holding devices with abody and alignment pins arranged therein is known from EP 0 761 382 A1.The alignment pins are inserted into holes at right angles to a clampingsurface of the body.

Several individually adjustable retaining screws for support against aworkpiece are arranged in threaded holes of the clamping jaw in aclamping device known from U.S. Pat. No. 824,394 A.

EP 1 375 069 A2 concerns a clamping device that contains a movableclamping element designed as a cylinder and a fixed clamping element.The fixed clamping element contains a housing having two blind holesleading obliquely downward arranged one above the other on the workpieceside. A clamping jaw outwardly biased by a compression spring isinserted into each of the blind holes.

A device for straight clamping of preferably cylindrical workpieces ofthe same diameter between clamping jaws movable parallel to each otheris disclosed in AT 288 283 B. For this purpose, at least one clampingjaw has notch-like clamping elements in a straight line arranged inseries.

SUMMARY

One aspect of the disclosure relates to a clamping jaw which facilitiesan optimal clamping effect, is favorable to manufacture, and permitsimproved accessibility even at limited clamping heights. Expedientembodiments and advantageous refinements are also disclosed.

The clamping inserts in the clamping jaw according to the disclosure aredesigned in the form of cylindrical pins projecting relative to an endsurface of the body and inclined with respect to a lower base surface ofthe body, forming a clamping edge for insertion of the clamping insertsinto the workpiece. A wedge-like clamping profile with upper and lowerembossed surfaces is thereby formed, which are pressed into theworkpiece and ensure good holding. Because of the oblique arrangement ofthe pin-like clamping inserts, they are only loaded in the pressuredirection and exhibit no or only limited bending load. The clampinginserts designed as cylindrical pins have a simple geometry and are thussimple to manufacture. Their mounting in a body is also simple andpossible with little effort. The clamping inserts, for example, can beinserted into holes in the body that are simple to produce andcost-effective. The clamping inserts consisting of sintered metal orsintered ceramic can have a hardness of up to HRC 90, so that evenworkpieces made of hardened steel can be reliably clamped. Thecost-effective clamping inserts are simple to mount and can be replacedquickly and simply, as required.

In a particularly expedient embodiment, the center axes of the clampinginserts designed as cylindrical pins are inclined at an angle of 40 to60° with respect to the base surface of the body. If the center axes ofthe clamping inserts designed as cylindrical pins are inclined at anangle of 45°, for example, with respect to the base surface of the body,almost identical upper and lower embossed surfaces are obtained so thata neutral clamping engagement is obtained without pull-down. At anglesof more than 45°, downward acting force components can be generated onthe clamping insert through which the workpieces can be forced downwardagainst a support surface.

The clamping inserts designed as cylindrical pins are preferablyarranged in several oblique mounting openings arranged next to eachother on the end surface of the body. The mounting openings can bedesigned as simple cylindrical holes and are thus simple to manufacture.

Particularly reliable holding of the clamping inserts on the body can beachieved by the fact that the clamping inserts are fastened by gluing,soldering, pressing, clamping or the like into the mounting openings ofthe body. In one possible embodiment, the clamping inserts can be heldagainst the body by a notch pressed into the body.

The mounting openings can be expediently designed as blind holes.However, ejection holes can also be provided on the mounting openings.Because of this, the clamping inserts, when necessary, can be simplychanged or replaced.

A particularly sharp clamping edge can be achieved by the fact thatclamping inserts designed as cylindrical pins have a flat outer endsurface. The outer end surface of the pin-like clamping inserts,however, can also be slightly conical or curved.

For clamping with low clamping height, a contact surface for support ofthe workpiece can be provided on the body beneath the clamping inserts.For clamping of larger workpieces, however, such a contact surface canalso be omitted. The end surface can then run at right angles to thebase surface without gradation.

In another expedient embodiment, the pin-like clamping inserts can bearranged in a concave plane, so that the outer clamping inserts engagedeeper into the workpiece than the inner clamping inserts. The tiltingmoments that develop during the clamping process can thereby beoptimally taken up by the outer clamping inserts. The clamping inserts,however, can also be arranged in a straight plane.

The clamping inserts can be arranged in one row or several rows.

BRIEF DESCRIPTION OF THE DRAWINGS

Additional details and advantages of the disclosure are apparent fromthe following description of preferred embodiment examples withreference to the drawing. In the drawing:

FIG. 1 shows a first embodiment example of a clamping jaw in a frontview;

FIG. 2 shows the upper part of the clamping jaw depicted in FIG. 1 in aperspective;

FIG. 3 shows a sectional view of the clamping jaw along line A-A of FIG.1;

FIG. 4 shows an enlarged depiction of the upper area of the view of FIG.3;

FIG. 5 shows the clamping jaw of FIG. 1 in a top view;

FIG. 6 shows the detail view depicted in FIG. 4 of a clamping jaw withworkpiece;

FIG. 7 shows a top view of the clamping jaw of FIG. 1 with workpiece;

FIG. 8 shows a detailed view of a second embodiment of a clamping jaw;

FIG. 9 shows a detailed view of a third embodiment of a clamping jaw;

FIG. 10 shows a detailed view of a fourth embodiment of a clamping jaw;

FIG. 11 shows a fifth embodiment example of clamping jaw in a side viewand

FIG. 12 shows the clamping jaw of FIG. 11 in a top view.

DETAILED DESCRIPTION

A first embodiment example of a clamping jaw 1 is shown in FIGS. 1 to 7for the clamping of a workpiece 2 depicted in FIG. 6. The clamping jaw 1contains a body 3 and several pin-like clamping inserts 5 arranged inmounting openings 4 of the body 3, which consists of a sinteredmaterial, preferably sintered metal or sintered ceramic.

The body 3 of clamping jaw 1 has a lower base surface 6 on its bottomrunning in the clamping direction of clamping jaw 1 and a step-likeshoulder on its side facing the workpiece 2 with a support surface 7parallel to base surface 6, an end surface 8 at a right angle to it anda chamfer 9. Several oblique mounting openings 4 arranged next to eachother are provided on the step-like shoulder of the body 3 toaccommodate the clamping inserts 5 designed in the form of cylindricalpins. The clamping jaw 1 in the embodiment depicted in FIGS. 1 to 7 isdesigned as a replaceable clamping jaw. The body 3 is therefore designedin the form of a plate and has two holes 10 depicted in FIG. 1 forfastening screws for releasable fastening of the clamping jaw 1 to theoppositely movable jaws of a vice or other clamping device. However, thebody 3 can also be screwed from above or designed as the jaw of a vice,for example, in the form of a block or the like.

As follows from FIGS. 3 and 4, the clamping inserts 5 designed ascylindrical pins are arranged in the body 3, so that their central axis11 runs obliquely toward the front end surface 8 of body 3 and alsoobliquely toward the lower base 6. The hole-like mounting openings 4designed as holes for the pin-like clamping inserts 5 projectingobliquely upward here are inclined obliquely downward relative to thefront end surface 8. The pin-like clamping inserts 5 have an edge 12 ontheir ends projecting opposite end surface 8 for insertion into theworkpiece. The edge 12 in the embodiment depicted in FIG. 4 is formedbetween a flat outer end surface 13 and the lateral surface 14 of thepin-like clamping insert 5. A particularly sharp edge 12 for goodcutting into the workpiece 2 is achieved by a flat outer end surface 13.The outer end surface 13 of the pin-like clamping inserts 5, however,can also be slightly conical or curved.

It is apparent in the top view of the FIG. 5 that the pin-like clampinginserts 5 are not arranged in a straight, but in a concave plane 15 sothat the outer clamping inserts 5 engage more deeply into the workpiecethan the inner clamping inserts 5. Because of this the tilting momentsthat develop during the clamping process are optimally taken up by theouter clamping inserts 5. A distance a is present between the innerclamping insert 5 and the corresponding outer clamping inserts 5. Thiscan be achieved, for example, by different alignments and differentlyprojecting clamping inserts 5. The clamping inserts 5, however, can alsobe arranged in a straight plane.

As is apparent from FIGS. 6 and 7, the pin-like clamping inserts 5 areforced against the workpiece 2 in the fashion of a wedge into thesurface of workpiece 2 during travel of the clamping jaw 1. Proper gripof the clamping jaw 1 and reliable holding of the workpiece 2 arethereby achieved.

The central axes 11 of the pin-like clamping inserts 5 in the embodimentdepicted in FIGS. 1 to 7 have an inclination of 45° relative to the basesurface 6 and to the clamping direction of clamping jaw 1. The embossedsurfaces formed by the outer end surface 13 and the lateral surface 14of pin-like clamping insert 5 therefore have the same inclination, sothat neutral clamping without pull-down can be achieved. At greaterinclinations of the central axes 11, on the other hand, the lowerembossed surface is larger than the upper embossed surface. Theworkpiece is thereby pulled downward against the support surface 7 whenthe clamping inserts 5 are forced downward. In preferred fashion, thecentral axes 11 of the pin-like clamping inserts 5 are inclined at anangle of 45° to 60° relative to the base surface 6 of the body 3 and theclamping direction of the clamping jaw 1. A support surface 7 providedon the body 3 beneath clamping inserts 5 is particularly suitable forsupport of workpieces that do not protrude too far. However, forclamping of larger workpieces such a support surface can also beomitted. The end surface 8 can then run at right angles to the basesurface 6 without gradation. In order for low clamping heights to alsobe clamped, the pin-like clamping inserts 5 designed as cylindrical pinspreferably have a small diameter of 0.5 to 5 mm, preferably about 2 mm.

Fastening of the pin-like clamping inserts 5 in the mounting openings 4of the body 3 can occur by gluing, pressing, soldering or anotherappropriate manner. In an advantageous embodiment, the clamping inserts5 can be designed so that they are force-fit by deformation of the body3, for example, by introducing a notch 16 depicted in FIG. 8 or a hole.

In order to facilitate changing of clamping inserts 5, an ejection hole17 depicted in FIG. 9 can be provided in the body 3. If necessary, aclamping insert 5 can be simply ejected and replaced via the ejectionhole 17 coaxial to mounting opening 4.

An embodiment example of a clamping jaw 1 with a body 3 and a pin-likeclamping insert 5, whose central axis 11 is inclined at an angle of 60°relative to the base surface 7, is depicted in FIG. 10. It is apparentfrom this depiction that the upper embossed surface formed by the outerend surface 13 of clamping insert 5 is smaller than the lower embossedsurface formed by the lateral surface 14 of the clamping insert 5.

FIGS. 11 and 12 show another embodiment example of a clamping jaw 1 witha body 3 and several pin-like clamping inserts 5 arranged in mountingopenings 4 of the body 3. In contrast to the previous embodiments, thebody 3 here is not designed as a replaceable plate, but as a clampingblock that can be fastened on a guide part. The body 3, as required, canbe turned around and has an upward projecting crosspiece 18 with two endsurfaces 8 pointing toward opposite sides. Obliquely upwardly projectingpin-like clamping inserts 5 are provided on the crosspiece 18 projectingtoward both sides. The clamping inserts 5 arranged on both end surfaces8 are offset here relative to each other.

LIST OF REFERENCE NUMBERS

-   -   1 Clamping jaw    -   2 Workpiece    -   3 Body    -   4 Mounting opening    -   5 Clamping insert    -   6 Lower base surface    -   7 Support surface    -   8 End surface    -   9 Chamfer    -   10 Hole    -   11 Central axis    -   12 Edge    -   13 End surface    -   14 Lateral surface    -   15 Concave plane    -   16 Notch    -   17 Ejection hole    -   18 Crosspiece

1. A clamping jaw for clamping of a workpiece, the clamping jawcomprising a body and a plurality of clamping inserts arranged inmounting openings of the body made of a sintered material, wherein theclamping inserts are designed in the form of cylindrical pins projectingrelative to an end surface of the body and inclined relative to a lowerbase surface of the body with a clamping edge for forcing the clampinginserts into the workpiece.
 2. The clamping jaw of claim 1, whereincenter axes of the clamping inserts are inclined at an angle of 40° to60° with respect to the base surface of the body.
 3. The clamping jaw ofclaim 1, wherein each of the mounting openings is oblique and themounting openings are arranged next to each other on the end surface ofthe body.
 4. The clamping jaw of claim 1, wherein the clamping insertsare fastened by gluing, soldering, pressing or clamping in the mountingopenings of the body.
 5. The clamping jaw of claim 1, wherein theclamping inserts are held against the body by a notch made in the body.6. The clamping jaw of claim 1, wherein the mounting openings aredesigned as oblique blind holes.
 7. The clamping jaw of claim 1, whereinan ejection hole is provided on each of the mounting openings.
 8. Theclamping jaw of claim 1, wherein each of the plurality of clampinginserts has a flat outer end surface.
 9. The clamping jaw of claim 1,wherein the body contains a support surface to support the workpiecebeneath the clamping inserts.
 10. The clamping jaw of claim 1, whereinthe clamping inserts are arranged in a concave plane.
 11. The clampingjaw of claim 1, wherein the clamping inserts are arranged in one row ora plurality of rows.